"This series of concerts embrace the original Thick As A Brick tour from 1972, but 40 years later. It's the best of Jethro Tull and also a few tracks from the new album Homo Erraticus," he says.

"It's a real mixture of theatrical performance and video. We try and make it entertaining and interesting for those people who like to get to bed early. We try and keep them awake a little while longer."

His band has been with him for many years, he says, and are capable of playing "every era" of Jethro Tull.

"You really have to be a broadly versed musician in the style and detail to assimilate all that knowledge and music.

"It's easy for me because I'm the guy that wrote it," Anderson says. "But they do get a wide variety of music to get their teeth into, assuming they still have their own."

Prog rock band Jethro Tull, named by their agent in the late 1960s after an 18th century English agricultural pioneer who invented the seed drill, formed in Luton, Bedfordshire, in 1967. They achieved world acclaim for their early 1970s albums Aqualung and Thick As A Brick.

Anderson, a one-time salmon farmer, believed he was destined to have "more fun being a flute-player than a fish-salesman".

Known for standing on one leg while he plays, Anderson recalls the circumstances that led to the purchase of his first flute.

"Well, I had just turned 20. Having been a guitar player in my teenage years I was aware that I was going to be a third-rate guitar player in the shadow of Eric Clapton, Jimmy Page or Jimi Hendrix. I decided to try another instrument and try to be a bigger fish in a much smaller pond.

"Flute was not uncommon in pop but it didn't play a lead role - it was more of a pretty, secondary instrument. In my case I thought maybe a flute could have a more strident purpose, so that's what I tried to do."

An impoverished Lemmy Kilmister - then of Reverend Black And The Rocking Vicars, later of Motorhead - had "charmed him to death" and, in exchange for cash, left him with a Fender Stratocaster guitar which had seen better days.

"It was a hire purchase arrangement of sorts. Finally I decided to trade the guitar back in for a Shure Unidyne III microphone from the United States - and, to make up the value of the store credit, I scanned the walls and my eyes fell on a shiny sparkling thing which was a student model flute.

"For no good reason whatsoever, just on impulse, I made the decision to acquire that.

"That was exchanged for a 1970s Strat which in today's money would be worth around $30,000 so financially speaking it was clearly a disaster, but, taking a longer view, I think I made a pretty good deal."

Looking back on a life spent on stage, Anderson says the moments that pop instantly to his mind are either "scary" or "tragic".

At a Bristol show a few weeks ago a man in the audience had a cardiac arrest.

"It took 20 minutes to get him going. He owes his life to members of the audience who jumped in and kept his heart manually working.

"It destroyed our show. It was tragic but memorable. Against all the odds, he survived.

"We do tend to have paramedics on hand. In the old days it used to be for teenagers overdosing on dangerous drugs - now it's senior citizens with dodgy tickers."

A performance in New York during the 1970s is also memorable.

At the time there was a lot of antagonism between audience members and police. Guns were frequently found on members of the audience and live ammunition was occasionally found on stage, he recalls. It set him on edge.

"On one particular occasion I remember feeling a blow to my chest. I was singing on stage and suddenly I felt something hit my chest. I looked down and there was blood everywhere, seeping through my shirt. I could see blood on my skin, coming through the shirt. I thought ‘this is what it feels like to be shot'. I couldn't feel any pain but I thought that was just the adrenaline kicking in."

He carried on singing. He recalls thinking that the pain would start and: "I will fall down and I will die."

But then he realised that he still wasn't feeling any pain.

"I thought ‘I've been shot but I can't feel anything'.

"I noticed, down inside my shirt, what seemed to be a little piece of string. I reached down and pulled out a used tampon which had been hurled at me in some act of devout, loving attention by some girl in the audience."

Anderson tells this story with a delicious laugh.

"Tom Jones has knickers thrown at him. I've gone one better."

Jethro Tull are also at the centre of what has been named the "biggest upset" in Grammy Awards history.

In 1988, the Hard Rock/Metal Performance category was added to the 31st Grammy Awards. The five nominees, "curiously", included Jethro Tull.

"I remember being quite surprised that we were nominated, but no-one thought we could possibly win, including our record company, because Metallica were the hot new band at that time and everyone assumed their hugely successful album would win.

"We didn't even go to the ceremony, we stayed at home."

Thousands of miles away in a studio in Britain, the band received a phone call telling them they had won the award.

"We thought ‘that's nice'. The next day we saw a story in the newspaper which included that the audience had greeted the announcement with howls of anger and derision.

"The voting members of the academy had decided in their infinite wisdom that they should award this gong to us, and not for being a hard rock/metal band, but probably because we were a bunch of nice guys who hadn't won a Grammy before.

"Since there is not a Grammy category for best one-legged flute player, it seemed appropriate to accept it."

Alice Cooper collected the award on behalf of Jethro Tull that night to the crowd's angry catcalls and boos.

But Anderson didn't get to thank him until 30 years later, when he randomly saw him at an airport.

"He did remember it as being a rather harrowing occasion."

Anderson gets bored easily. He says the idea of not performing or creating music, having done so for four decades, feels "quite threatening".

"For me it's about engaging with whatever creative juices I might have left. I will try to push the boat out a bit in the next four or five years. I fear aged 70-something I might find it a little more daunting to do what I do right now.

"But at the moment things are fine, I have my health and most of my marbles are intact.

"While I have my marbles I'm going to play with them."

THE DETAILS:

Jethro Tull at Isaac Theatre Royal on December 18; Wellington's St James Theatre on December 19 and Auckland's The Civic on December 20. Tickets are available from Ticketek (03) 377 7799 or Ticketmaster (09) 970 9700 for the Auckland concert. Tickets go on sale, Monday.